Ignition only

[Bruce Plecan]

Try firing a dissy with one spark.
DIS can
Distributor has them in series so they both have to happen
DIS they are parrarel, either is *independent* of the other
case closed

Dual coils, a new definition.
Maybe a coil with dual HV leads.  Maybe a 4 lead coil, vs 3.
Autotranformer has "dual coils" with a common connection
So far as conventional ignitions all I've seen is a primary and secondary
winding.
So they are all dual coils

> > Ooops, meant to delete this off list

> A wasted spark DIS uses special "dual" coils which have HT leads connected
> to both ends of the secondary (high voltage) winding, unlike a
conventional
> coil were one side is grounded. Both HT leads are connected to a different
> plug (cyl 1 and 4 on a 4 cyl engine, another dual coil taking care of cyl
3
> and 2, assuming 1-3-4-2 firing order). When one coil fires, both cylinders
> connected to it fires at the same time. On one of the cylinders, the spark
> jumps from the central electrode of the plug to the ground electrode, the
> current then travels though the head and another spark jumps in the other
> direction through the second plug (from the ground electrode to the
central
> electrode, effectively crossing a second gap) then returns to the coil
> through the second HT lead, closing the loop. Technically, the engine
> doesn't need to be grounded for this to work, unlike conventional ignition
> systems where the current returns through the engine and chassis. One of
the
> cylinders is at the end of the compression stroke and the other, where the
> second - wasted - spark occurs, is at the end of the exhaust stroke where
> pressure is near atmospheric, thus that other spark consumes very little
> current.

near atmospheric?.
Oh we'll just ignore street turbo stuff
Oh on a distributor the spark doesn't have to go thru the block,  I've been
zapped an the path was coil coil wire, me, chassis,

> In other words, a wasted spark DIS doesn't save you a gap compared to a
> distributor based system. It just moves it.
> Need more complete descriptions? Please check

Just show me a single spark distributor ignition........
Cheers
Bruce

> http://www.asashop.org/autoinc/feb97/DIS.htm
> http://www.ag.auburn.edu/users/gparmer/efi/myfaq.htm
> Regards,
> Axel

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